REPORT ON CORALS — DEEP-SEA MADREPORARIA. 



lOiJ 



septum, curved lines of septal matter are formed which are fused by short, transverse, 

 synapticular laminae to the primary septa, at points very near the centres of the lengths 

 of each of these. Thus is brought about the peculiar arrangement which forms the most 

 striking feature presented by the adult coral, and which consists in the presence around 

 the elongate columella of six symmetrically arranged oval hollow spaces, each of which is 

 enclosed by a loop-like lamina, as it were, of hard tissue, and bisected longitudinally by 

 the inner end of the palus of the corresponding primary septum. 



Shows the arrangement of the septa in the adult and young Stephanojyhyllia complicate. The specimens were taken 

 September 26, 1S74, in 129 fathoms, off the Ki Islands. 



A. Adult, diam. 1 7 cm. B. Young, diam. 6 mm. 



In their further course, the tertiary septa are. bent from side to side in a most 

 remarkable manner, and fusing at successive distances outwards with the shorter quater- 

 nary and still shorter quinary septa, which are likewise extremely undulate in their 

 course, a series of chambers is formed, which chambers are closed at their peripheral ends 

 by processes of synapticular matter. The chambers are arranged symmetrically in each 

 system on either side of the secondary septum, and successively decrease in size and 

 increase in number from the centre outwards. The chambers opening all over the coral 

 give it a most remarkable honeycombed appearance. 



The columella is an elongate, thin, vertical lamina stretched in line with an opposite 

 pair of primary septa. At its base it is provided with rootlets, which join the primary 

 and fused tertiary septa. 



